He was born at the Edo residence of the Sakura domain, the second son of lord Hotta Masatoki. His first name was Masahiro. His father died the next year, and he was later adopted by the lord who had succeeded. As a boy he was sturdy and loved small birds, delighting in feeding them. He is said to have lived freely at the residence with his mother and sister.
Within the domain, a powerful elder retainer tried to install someone else as lord, but partly because lower-ranking samurai opposed this, Masahiro succeeded as lord of Sakura. As lord, he promoted retainers who had supported him and gradually strengthened his own position. It was a difficult start.
When the elder retainer who had controlled the domain died, Masahiro stood on his own as lord and pushed reforms. He promoted Dutch learning (rangaku) so eagerly that he was called a "Dutch enthusiast". Through these efforts, he laid the foundation for Sakura to become a center of learning that produced many talented people.
After being appointed keeper of Osaka Castle, he soon became rōjū for the western enclosure of Edo Castle. He had already gained experience as a shogunate official, serving as sōjaban and magistrate of temples and shrines. While pursuing reform as lord, he joined the center of shogunate politics, and his ability drew attention.
He became rōjū for the main enclosure and took part in the Tenpō Reforms led by the chief rōjū Mizuno Tadakuni. But Masahiro was critical of Tadakuni's harsh pressure on the common people and is said to have foreseen early on that the reforms would fail. It was a time when he deepened his own views on how the shogunate should govern.
Foreseeing the reforms' failure, he resigned as rōjū, citing illness. Tadakuni was dismissed soon after, so Masahiro's quick judgment spared him from downfall. Returning to Sakura, he focused on reform and invited the Dutch-style doctor Satō Taizen to open Juntendō, a school of medicine. Juntendō continues to this day as a university.
A great earthquake struck Edo, and Masahiro was injured at his residence. A week later, on the recommendation of the chief rōjū Abe Masahiro, he became rōjū again, was handed the top position and took charge of foreign affairs. As he favored opening the country to trade, Tokugawa Nariaki, who advocated expelling foreigners, is said to have opposed his appointment.
The year before, out of respect for Atsuhime, who had married the shogun Iesada, he had changed his name from Masahiro to Masayoshi. This year he arranged the US consul general Harris's audience with the shogun and advanced negotiations on a trade treaty. Believing foreign trade unavoidable, Masayoshi sought to open the country for a new era.
To conclude the Harris Treaty, he went to Kyoto to seek imperial sanction from Emperor Kōmei. But because of opposing court nobles and the emperor's own wish to expel foreigners, approval was refused, and he returned to Edo empty-handed. Meanwhile Ii Naosuke had become tairō, and he removed Masayoshi from the post of rōjū.
He handed the headship to his fourth son, retired and took the name Kenzan. This retirement is said to have been linked to the punishment of those who opposed Naosuke over the shogunal succession. Yet in the Ansei Purge, while other daimyo were severely punished, Masayoshi received no heavy penalty.
After Ii Naosuke fell in the Sakuradamon Incident, Masayoshi was ordered by both the court and the shogunate to remain in confinement at Sakura Castle. This penalty was meant as retaliation for Naosuke's Ansei Purge. Masayoshi, who had pushed for opening the country, was again kept from the public stage amid violent political swings.
Still in confinement, he died in a residence in the third enclosure of Sakura Castle. The confinement was lifted soon after his death. Facing the difficult decision of opening the country, and valuing Dutch learning (rangaku) to make Sakura a town of learning, Masayoshi was a statesman who bore heavy responsibility at a turning point in history. His grave is at Jindai-ji in Sakura.
Mizuno TadakuniTokugawa NariakiTownsend HarrisAbe MasahiroIi Naosuke
Fujita TokoShimazu NariakiraYokoi ShōnanOgata KōanSakuma ShōzanIi NaosukeNabeshima Naomasa (Kansō)Yoshida Tōyō
People of the Edo period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.